If you've ever been through the famed Kentucky Bourbon Trail, there might have been one sight you missed: a "black gunk" that's been showing up not only in the distilleries, but in surrounding homes. Well, Kentucky residents are so angry about what's been called the "whiskey fungus" that they're suing Louisville distilleries for property damage and negligence.

Reports The New York Times, this fungus is primarily a byproduct of the whiskey-making process; the Baudoinia fungus germinates on ethanol, which usually evaporates during fermentation. Therefore, it feeds on what's called the "angel's share," aka the evaporated amount of elixir that is released while whiskey ages in barrels. The fungus is rampant in these Louisville distilleries, according to experts; it's why homeowners have filed a class-action lawsuit against the Brown-Forman, Diageo,and Heaven Hill distilleries.

There's no evidence the "whiskey fungus" has any major impact on health, although it might deter plant growth. Still, homeowners claim that the gunk is impossible to get rid of in their homes and cars. The distilleries released a statement that they will be fighting the lawsuit, claiming they haven't caused real harm to anyone's property.